cyphesis/data/deeds/structures/structure.xml

<atlas>

  <map>
    <map name="attributes">
      <map name="simple">
        <int name="default">0</int>
        <string name="visibility">public</string>
      </map>
      <map name="density">
        <float name="default">2000</float>
        <string name="visibility">public</string>
      </map>
    </map>
    <string name="id">structure</string>
    <string name="objtype">class</string>
    <string name="parent">thing</string>
  </map>

</atlas>